In electronics, a flip-flop is a circuit that has two stable states and can be used to store digital information. Flip-flops are a fundamental building block of digital electronics systems and are used to store data in computers, communications, and many other types of systems. A flip-flop includes an input terminal on which data to be stored is received, a clock terminal on which a clock signal is received, and an output terminal at which data stored in the flip-flop is delivered.
A flip-flop typically stores a single bit (binary digit) of data, as evidenced by two different states. One of its two states represents a “one” and the other represents a “zero”. Thus, the output terminal of the flip-flop produces a signal that “flips” and “flops” between the “one” state and the “zero” state in a manner that depends on the input data and the clock signal provided to the flip-flop. Flip-flops can be used for any number of applications in electronics circuits, such as counting of pulses, storing data values, and/or synchronizing variably-timed input signals to some reference timing signal.